The US soldier Bradley Manning is likely to receive a stiff sentence after he was found guilty of espionage for handing over a trove of documents and videos to WikiLeaks. It was the largest unauthorised release of classified material in the country's history.

Transcript

MARK COLVIN: The US soldier Bradley Manning is likely to spend much of the rest of his life in military jail after he was found guilty of espionage for leaking to WikiLeaks.

It was the biggest unauthorised release of classified material in the country's history.

The US government has been pushing for a life sentence with no possibility of early release.

But the international human rights lawyer Geoffrey Robertson says that would be cruel, distasteful and out of step with more moderate jail terms given to US soldiers who committed major crimes during wars in Iraq and Vietnam.

Brendan Trembath reports.

BRENDAN TREMBATH: At Fort Meade outside Washington, a slightly built US soldier is brought before a military court.

Private first class Bradley Manning wears a dress uniform while the armed men escorting him wear smart casual civilian clothes and sunglasses.

In a five minute hearing he was found guilty of most of the charges against him, for the largest unauthorised release of classified material in US history.

Former US State Department spokesman P.J Crowley says it's the right decision.

PJ CROWLEY: In the military justice system what's important here is sustaining good order and discipline. Bradley Manning was charged and in fact admitted to conveying this information, and in doing so he violated his responsibility as a soldier in a war zone.

BRENDAN TREMBATH: PJ Crowley spoke to Al Jazeera.

He's previously argued that a sentence of 20 years would be appropriate, and anything more excessive.

PJ Crowley says the United States deals with leaks all the time, but this was an unprecedented case.

PJ CROWLEY: It's important to understand that Bradley Manning did significant damage; among other things he put the lives of real people and the careers of real people at risk.

These were individuals who had perhaps talked to soldiers in a war zone, or diplomats, or activists who talk to US diplomats around the world so that the American administration could understand what's happening in the world and have perspective.

And in doing so - particularly in autocratic societies - they put these people's lives at risk, and in some cases they still remain at risk.

BRENDAN TREMBATH: The information ranged from 250,000 diplomatic cables to battlefield reports from Iraq and Afghanistan.

The war reports included videos of a 2007 attack by an American helicopter gunship in Baghdad that killed a dozen people.

Bradley Manning was found not guilty of aiding the enemy - the most serious charge against him.

But observers familiar with the US military justice system know he's still in hot water.

Dan Mori is a former US Marine Corps lawyer and now consultant to the Australian firm Shine Lawyers.

DAN MORI: There's going to be some argument on whether different crimes - offences he's been found guilty of or plead guilty to - should be merged and whether that would reduce the number of years for the maximum.

But in the military there's no minimum sentence, and so there'd be a wide range - but I don't expect him to get sentenced to anything more than 10; that wouldn't shock me if he gets less than 10 years. It would shock me if he gets over 20 years, and I think that would be probably very extreme.

GEOFFREY ROBERTSON: I would hope that there would be very modest and merciful sentence on this young man who was, in the first place, activated by conscience. But we wait and see, and the debate will go on.

BRENDAN TREMBATH: Geoffrey Robertson is already turning his mind to possible grounds for an appeal.

GEOFFREY ROBERTSON: This judge is a colonel in the military that is bringing the case, so she's not a real judge, not an impartial judge, interestingly enough. And I think cleverly and rightly David Coombs, who's the lawyer for Manning, opted for a judge alone rather than a panel of fellow officers who'd be totally prejudiced against Manning. But his fate is in a military court.